Dam.



PATENTED NOV. 12, 1907 H. L. COBURN.

DA M.

APPLIOATION FILED JULY 19 JWW Q a.

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UNITED STATES HOWARD L. COBURN, OF

PATENT OFFICE.

BOSTON, MASSACHUSETTS.

DAM.

Application filed July 19 1905.

Specification of Letters Patent.

To all whom "it may concern:

Be it known that I, Howanu L. Census, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Dams, of which the following is a specification.

This invention has for its object to provide a hollow concrete dam, which shall possess the requisite strength and stiffness. without being provided with transverse buttresses between its deck or upstream wall. and its apron or downstream wall.

The invention consists in a hollow concrete darn, comprising an inclined deck, an oppositely inclined apron or strut, both rising from a suitable base or support and meeting over the support to form a crest and reinforcing members so disposed in said deck and apron that no transverse internal buttresses or partitions are required to support the deck and apron against the strains to which they are subjected.

The invention also consists in a darn clnu'acterizcd as above indicated, and provided with a floor extending between the bases of the deck and apron and reinforcing members so disposed in the said floor as to prevent the spreading of the dam and the bending or buckling of the floor.

Of the accompanying drawings, forming a part of this specification,-Figure 1 represents a perspective sectional view of a dam embodying my invention. Fig. 2 represents a fragmentary perspective sectional view, showing portions of the floor and apron.

The same reference characters indicate the me parts" in both the figures.

In the drawings.-12 represents a concrete, floor. which is substantially horizontal. and rests upon-the bed of the stream, said floor preferably having downwardly extending cut-off portions 13 and 14 at its upstream and downstream edges.

15 represents the inclined deck, which is an impervious slab rising from the upstream portion of the floor or from any other suitable foundation, and inclined in the direction of the flow of the stream so that it overhangs the floor. 16 represents the apron, which is also an impervious slab rising from the downstream portion of the floor and having an opposite inclination from that of the deck, the said deck and apron meeting to form the crest 17, which is located above the central portion of the floor. The apron serves to ease the overflowing water down to the bed of the stream. and also serves as a strut to transfer the thrusts brought upon it by the weight of the deck and its superimposed load of water. to the foundation.

The floor, deck, and apron are preferably formed integral with each other, from concrete or an equivalent composition. The floor is provided with reinforcing rods 19 20 which extend crosswise of the dam or from the upstream to the downstream portion of the floor, the rods 19 being adjacent to the upper surface, and

the rods 20 to the lower surface of the floor. The deck 15 is provided with inclined rods 21. preferably located near the inner surface of the deck, and extending substantially parallel therewith from the base to the crest. crosswise of the deck. The apron is provided with a series of inclined inner reinforcing rods 22 which may be extensions of the rods 21, and

a series of inclined outer reinforcing rods 23, the rods 21, 22 extending from the base to the crest crosswise of the apron.

The only stresses set up in the deck 15 are bending stresses due to water pressure on the outer face of the deck. The reinforcing rods 21 are located in close proximity to the inner face of the deck and much nearer the inner than the outer face as shown. Any vertical element of the deck thus becomes a beam supported at the ends and the disposition of the reinforcing rods enables said beam to resist the bending pressure to which the deck is subjected, the rods being thrown into tension by said pressure.

In the strut or apron 16 the stresses are both bending and crushing, due to the pressure of the deck upon the upper or crest portion of the apron, this pressure tending to buckle or deflect the apron laterally either inwardly or outwardly. To enable the apron to resist these strains, I provide it with thetwo series of reinforcing rods 22, 23. The rods 22 of one series are located in close proximity to the inner face of the apron while the rods 23 of the other series are located in close proximity to the outer face of the apron, the rods of both series being inclined and extending from base to crest crosswise of the apron as above stated. The described location and arrangement of the rods 22, 23 enable them to resist both the bending and crushing strains and pre-' vent sidewise deflection or buckling of the apron in either direction, said rods making the apron particularly effective as a strut supporting the deck and crest.

The reinforcing rods 19 and 20 in the floor extend crosswise of the floor or from edge to edge thereof, and are arranged in two series, the rods 19 of one series being in close proximityto the upper side of the floor while the rods 20 are located in close proximity to its lower side. The rods 19 and 20 are enabled by this lo? cation and arrangement to prevent lateral deflection or buckling of the floor due to the weight of the deck and apron and the load on said parts exerted on the edge portions of the floor, so that no internal buttresses are required to prevent upward deflection or buckling of the floor from this cause, the reinforcing rods compensating for absence of internal support, although it is obvious that such internal support may be provided if desired. The arrangement of the said rods crosswise flow of stream, an oppositely inclined slab 01' heel portion of the apron. All the reinforcing rods or members are preferably formed to interlock with the i concrete in which they are embedded, the rods having I protuberances or projections located at suitable dis- J tances apart. I 5 The reinforcing members 22 and 23 in the apron or I strut 16 may be termed compression members'because they resist strain or pressure exerted on the apron in the direction of the length of said members, In case, however, the apron is subjected to pressure tending to bend or buckle it sidewise, the reinforcing members at the side of the apron toward which the buckling pressure is exerted become tension members. In case the natural bed of the river is composed of ledge the floor 12 will not be required.

I claim: 1. A dam comprising an impervious deck slab rising from suitable foundations and inclined in the direction of apron meeting the deck slab to form the crest of the dam, the said I apron being of a strength and standing at an angle to prevent the overturning of the deck by the weight of water I resting thereon, said deck and apron forming an unobstructed, interior.

2. A dam consisting of a slab or deck of impervious material, inclined in the direction of the flow of the stream, engaged at its lower edge with the foundation of the dam, and an oppositely inclined slab supporting the upperedgo of the deck and forming an apron for easing the overflowi ing water down to the bed of the stream and a strut to transfer the thrusts brought upon it by the weight of the I deck and its superimposed load of Water to the foundation, I said deck and apron forming an unobstructed interior. I

3. A dam consisting of a deck slab of concrete having its lower edge locked into the foundation bed so as to pre vent the passage of water thereunder, its upper edge supported by a suitable continuous strut transmitting the pressures to the foundation or bed, said deck slab being so reinforced by rods running vertically as to resist all bending stresses due to the superimposed load of water without the assistance of any tween the bottom and top edges thereof, said strut being of a strength and standing at an angle to resist \vaterpressure against the deck without internal bracing.

4. A dam consisting of a base, an inclined deck and an oppositely inclined apron, both rising from the said base and meeting at the crest to form a self-supporting structure, the said deck and apron being constructed of concrete or other suitable material, and forming an unobstructed interior.

A dam consisting of a slab or deck of concrete or other suitable material extending continuously across the I channel of the stream from abutment to abutment, supported at its lower edge by the bed or foundation into i which it is locked and prevented from overturning under action of the water pressure by a continuous strut rising from the base and meeting the upper edge of the deck to form a crest, said deck slab being suitably reinforced to resist bending or buckling between its supported edges, said deck and apron forming an unobstructed interior.

6. A hollow dam comprising an inclined deck, an oppo sitely inclined strut or apron meeting the deck at the crest of the dam, and inclined reinforcing members in the said deck and apron extending from the base to the crest of the dam, the members in the deck being arranged to resist bending stresses due to water pressure on the outer surface of the deck, while the members in the apron are ar ranged to resist bending and crushing stresses due to the pressure of the deck against the apron, the said reinforcing members compensating for the absence of interna supports within the space covered by the dam.

7. A hollow dam comprising an inclined deck, an oppositel-y inclined strut or apron meeting the deck at the crest of the dam, said parts being free from supports within the space covered by the dam, a series of inclined reinforcing members located in the deck in relatively close proximity to its inner face, and two series of inclined reinforcing members located in the apron, one near the inner face and the other near the outer face thereof, the reinforcing members of both deck 'and apron extending from base to crest crosswise of the deck and apron.

S. A hollow dam comprising an inclined deck, an oppositely inclined strut or apron meeting the deck at the crest of the dam, and a floor orfoundation integral with the deck and apron, deck and apron, extending, from the base to the crest of the dam and arranged to compensate for the absence of internal supports for the deck and apron within the space covered by the dam, and transverse reinforcing rods in the floor extending crosswise of the dam, said members being arranged to compensate for the absence of internal supports by preventing deflection of the floor due to the load on the edge portions thereof, and to prevent the base of the. structure from spreading.

9. A hollow dam comprising an inclined deck, an oppositely inclined strut or apron meeting the deck at the crest of the dam, and a floor or foundation integral with the deck and apron, inclined reinforcing members in the deck and apron extending from the base to the crest of the dam and arranged to compensate for the absence of internal supports for the deck and apron within the space covered by the dam, and two series of reinforcing rods in the floor, one series located near the upper face and the other near the lower face, and the rods of both series extending crosswise of the floor.

In testimony whereof I have aflixed my signature, in presence of two witnesses.

HOWARD L. COBURN. Witnesses ARTHUR H. BROWN. E. BATCHELDER.

inclined reinforcing members in they 

